Show rubber growth experiment rubber plants that are native to dry regions are being tested in call foila in the coast districts as well as in the interior valleys several dry country rubber plants are known in mexico while others are reported in south america africa and BIad agns car the production of rubber from the mexican guayule plant parthena Part henl urn has been ed carefully by a private corporation and the stage of agricultural Is believed to have been reached in california the guayule rubber plants in arizona and callior ala amount to several hundred acres |